A fender liner described in Patent Document 1 shown below is configured to include an arch portion that is formed along a wheel house, an introduction port that is provided at a front end portion of the arch portion, and an exhaust port that is provided at a rear end portion of the arch portion. Besides, the fender liner has a hollow portion through which the air caused to flow into the introduction port is introduced to the exhaust port. The hollow portion is held in communication with the interior of the wheel house by a plurality of suction holes that are formed through the arch portion.
Then, during traveling of a vehicle, air is caused to flow into the hollow portion from the introduction port, the air in the wheel house is sucked from the suction holes into the hollow portion, and the air in the hollow portion flows backward with respect to the vehicle to be discharged from the exhaust port.